You can easily change its writing style: https://code.claude.com/docs/en/output-styles

You can also customize further by putting notes in your global MD.

In my experience, no amount of output style customization gets it anywhere near the output I'd like.

I've had more success running a prose linter[1] with a ruleset[2] that gets rid of most of the egregious stuff. You can also pretty easily write custom rules for it.

And sometimes, when I'm fed up enough, I just throw all the prose in the codebase at Antigravity/Gemini to rephrase. The result is so much more readable.

[1]: https://vale.sh/

[2]: https://github.com/tbhb/vale-ai-tells

You can change it ... and Claude will maybe pay attention to what you changed 25% of the time.

"You can tell an AI model to write in a different style" and "the AI model will actually write in the style you tell it to" are two different things that often don't intersect